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OHSU Researcher Finds Signs of Brain Cell Growth

06/18/99 Portland, Ore.

Early study suggests brain's nerve cells may regenerate, even in old age

An Oregon Health Sciences University researcher today will present his findings that brain cells may continue to grow in humans, even in old age. The study bucks the trend of conventional scientific wisdom, which has held that nerve cells that reside in the brain stop growing shortly after birth.

"Even though neural cell growth has been documented in some animal species, it has been thought that humans did not have the capacity to grow new brain cells," said Melvyn Ball, M.D., professor of neuropathology at OHSU. "Only in the last year has there been any evidence that this might be possible."

Ball directs the Oregon Brain Bank, which accepts organ donations from state residents for study of the characteristics of the brain. His research focuses on Alzheimer's Disease and other forms of dementia that affect the brain's neurons or nerve cells. His study looked at the number of neural cells in three areas of the hippocampus, the "memory center" of the brain.

Using tissue samples from 22 people who died in the age ranges of 42 to 104, Ball and his colleagues found that, as expected, neural cell numbers declined as age increased in two of the regions. But in the third area, the dentate, the number of neural cells appeared to increase. In fact, brains showing the highest counts of dentate cells were from patients who had died between 85 and 100 years old.

"This is very preliminary, and we're not sure what this means, but if the trend holds out in larger studies, we could be on the verge of some new ways of thinking about the brain," Ball said.

Ball credits his discoveries to advances in a method of cell counting called stereology. Recent computer and software developments make it possible to count cells in three dimensions, leading to much more accurate and unbiased counts.

Ball will present his findings at a conference of the American Association of Neuropathologists, taking place this weekend in Portland. His findings will be presented at a poster session from 2 to 5 p.m. today in the Grand Ballroom of the Hilton Hotel.